The reality is that it doesn’t matter how many parties you have. What matters is whose interests these parties represent, which is governed by who has actual political leverage. In pretty much every western society, large capitalists are the ones who control the political system. These are the people who own the media, pay for political campaigns, lobbying, and other forms of political influence. The working majority has little leverage within a system where money plays such a disproportionate role. The political system is built by the class that holds power in society and it’s built to function in the interest of this class.